SYSTEMATIC AND DESCRIPTIVE. 231 



characterised by a thick false membrane, extending 

 over the fauces, larynx, and trachea. They occupied 

 the deeper layers below the masses of bacteria 

 which are found on the surface, such as the 

 Streptococci already described (p. 202). 



METHOD OF STAINING THE BACTERIA IN DIPHTHERIA. 



Lofflers Method: 



Sections are placed in Loffler's solution for a few minutes, 

 and excess of stain removed by \ per cent, solution of acetic 

 acid. They are then treated with alcohol and cedar-oil, and 

 mounted in Canada balsam. 



Bacterium saprogenes {Bacillus saprogenes 

 No. 3, Rosenbach). Rods isolated from the putrid 

 marrow of a case of compound fracture. Cultivated 

 on nutrient agar-agar, an ash-grey, almost liquid 

 culture is developed, with a strong characteristic 

 odour of putrefaction. Injected into the knee joint 

 or abdomen of a rabbit, an opaque, yellowish-green 

 infiltration resulted (vide Bacillus saprogenes^ p. 314). 



Bacterium decalvans, Thin. Cocci, singly or 

 in pairs, 1*6 p, in length. Observed in the roots of 

 the hair in cases of Alopecia areata. 



Bacterium in diphtheria of calves (Bacillus 

 vitulorum, Loffler). Rods about five or six times as 

 long as wide, mostly united in long threads. A 

 piece of tissue placed on blood serum developed a 

 white layer composed of the bacilli. Successive 

 generations were not obtainable. Mice inoculated 

 directly from the calf died of a characteristic illness, 



